ISLAMABAD: The government is likely to take action against Chief Executive Officer (CEO), Guddu power plant, Hammad Hashmi for being responsible for tripping due to earthing of plant's breaker.
A team of National Transmission and Despatch Company (NTDC) is already at the site to investigate reasons for a major power breakdown which led to nation-wide power blackout. It will submit its report in a day or two. The government has already suspended seven employees of Guddu Power Plant.
The sources said, the employees were carrying out maintenance of a circuit-breaker installed in the switch yard, whose earthing was done. This was done without prior approval of the NPCC (National Power Control Centre). The day shift of employees left the breaker without switching it off while the employees of night shut the circuit breaker without ending earthing.
"Circuit breaker of the power plant was shut down improperly due to which the entire system came down," the sources added.
The plant was shut down for closing the breaker without removing the earthing, due to which the transmission line from Guddu power plant tripped.
"As we receive a detailed report, actions will be taken at the top level," said an official of Power Division on condition of anonymity.
However, some power sector experts are not satisfied with this being the cause for tripping of the whole grid system, i.e., earthing by mis-operation of one of isolator at Guddu power station.
These experts, who have requested anonymity, argue that human error is a worldwide phenomenon though there should be proper check prior to clearance of PTW.
One of the stated: "In Pakistani grid single unit large 660MW and Kanupp2 1200 MW were installed in previous years, and the question is whether we did any study that in winter when the load on the grid is around 10,000 MW if a single large unit trips, what would be the frequency of the system after rejecting more than 10% from the system?"
According to him, when the load is rejected by the system frequency meter goes up and then comes down. System operator intervenes to stabilize the frequency which was near 45 hertz either by increasing load on machine or by load shedding. Due to this action frequency again goes up to 50 Hertz and stabilizes at the rated frequency. Second time frequency again starts dropping and reaches near to 45Hertz and then drops to zero. "It is important to check what happens the second time. Due to earthing of one isolator at one of the stations the whole system collapsed, which is not acceptable."
Copyright Business Recorder, 2021